Is: ?816 ( Part II)= WM (Rcd'tbned 1993) ( Reaffirmed 2003 ) Indian Standard METHODS OF TEST FOR `R''"'"* `"8) COATED AND TREATED FABRICS PART U DETERMINATION OF BREAKING STRER@TH AND EXTENSIOIIi AT BREAK ( First Revhion ) Seemd Reprint SEPTEMBER 199S UDC 67?865*2 : 677'01?424"5 @ Cupyright 1981 BUREAU OF INDIAN STANDARDS MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG NEW DELI-II 110002 IS : 7016 ( Part II ) - 1981 Indian Standard METHODS OF TEST FOR COATED AND TREATED FABRICS PART II DETERMINATION OF BREAKING STRENGTH AND EXTENSION AT BREAK ( First Reoision ) Treated Chairman SHRI S. L. GANDHI Members SHRI M. L. BAHRANI Fabrics Sectional Committee, PCDC 16 Ministry Representing of Defence ( R & D ), New Delhi Lr-COL R. G. WAS~RAD SHRI A. K. BANDOPADHYA ( Alternates to Shri S. L. Gandhi ) Ministry of Defence ( DGI ), New Delhi of Supplies and Disposals, Directorate General New Delhi SHR~P. L. NAG ( Alrernute ) SHRI A. T. BASAK SHRI A. R. HALDAR( Akernute ) Basant Pran Electric Co Pvt Ltd. Calcutta SHRI BASANT KUMAR SHRI J. S. NARULA( Alternate ) Bayer ( India ) Ltd. Bombay SHRI D. J. BHARUCHA SHRI K. I. JANAKAR( Alternate ) National Organic Chemical Industries Ltd, Bombay SHRI T. S. BIDDAPA SHRI J. K. VADODARIA ( Alternate ) Bengal Waterproof Works ( 1940 ) Ltd. Calcutta SHRI B. DUT~A ( Alternate ) National Test House, Calcutta SHRI A. GHOSH JOINT DIRECTOR OF MINESSAFETY Directorate General of Mines Safety, Dhanbad SHRI S. C. BATRA( Alternate ) Caprihans India Ltd, Thane SHRI Z. S. KAIIJI Ministry of Railways, New Delhi DR S. P. MANIK SHRI P. K. MUNSHI ( Alternate ) Ahmedabad Textile Industry's Research Association, SHRI J. R. MODI Ahmadabad Bhor Industries Ltd. Bombay SHR~ RAMANM. PAT~L SHRI K. L. SHAH ( Alternate 1 SHRI A. BOSE ( Contbucd on page 2 ) @ Copyright 1981 BUREAU OF INDtAN STANIM-S This publication is protected under the Indian Copyright Act ( XIV of 1957 ) and reproduction in whole or in part by any means except with written permission of the publisher shall be deemed to be an infringement of copyright under the said A& IS : 7016( Part II ) - 1981 ( Continued from pqge 1 ) Members Representing Central Warehousing Corporation, New Delhi SHRI P. RAMDA~ SHRI S. SAMPATHKUMAR ( Alternate ) Fibreglass Pilkington Ltd, Bombay SHRI G. H. RODRICKS East India Rubber Works Pvt Ltd, Calcutta SHRI B. ROY Directorate General of Technical Development, SHRI P. P. SHARMA New Delhi SHRI N. K. A~ARWAL ( Alternate ) Varrna Industries Ltd, Bangalore SHRI K. SRINIVASAN Director General, ISI ( Ex-oficio Member ) SHRI M. S. SAXENA, Director ( P & C ) Secretary SHRI V. S. LAL Deputy Director ( P & C ), IS1 Methods of Test for Treated Fabrics Subcommittee, PCDC Ih : 6 Convener SHRI S. L. GANDHI Ministry of Defence ( R & D ), `New Delhi Members SHRI M. L. BAHRANI( Alternate to Shri S. L. Gandhi ) Calico Chemicals, Plastics and Fibres Division, DR B. R. C. ANAND Bombay SHRI S. MITRA ( Alternate ) Directorate General of Supplies and Disposals, SHRI A. T. BASAK New Delhi SHRI P. K. BASU ( Alternate ) Madura Coats Ltd, Madurai SHRI A. CHELLAKAJ SHRI S. GNANASEKHARAN ( Alternate ) National Test House, Calcutta SHRI A. GHOSH Ministry of Railways, New Delhi DR S. P. MANIK Ministry of Defence ( DGI ). New Delhi SHRI P. L. NACZ SHRI H. L. SRIVASTAVA ( Alternate ) Shri Ram Institute for Industrial Research, Delhi Da J. K. NIGAM SHRI K. K. JUNEJA( Alternate ) Bayer ( India ) Ltd. Bombay DR S. Y. PANDIT DR P. V. RAIKAR ( Afternate ) Synthetics and Chemicals Ltd. Bombay SHRI M. M. PATEL SHRI R. K. NAYAK ( Alternate ) East India Rubber Works Pvt Ltd, Calcutta SHRI B. ROY Bhor Industries Ltd, Bombay SHRI J. M. SHROPF Caprihans India Ltd, Bombay SHRI S. K. VERMA SHRI Z. S. KAJIJI ( Alternate ) ( Continued on page 7 ) a " 2 IS : 7016 ( Part 11) - 1981 Indian Standard METHODS OF TEST FOR COATED AND TREATED FABRICS PART II DETERMINATION .OF BREAKING STRENGTH AND EXTENSION AT BREAK ( First RetiEon ) 0. FOREWORD 0.1 This Indian Standard (Part II) (First Revision ) was adopted by the Indian Standards Institution on 13 March 1981, after the draft finalized by the Rubber Products Sectional Committee had been approved by the Petroleum, Coal and Related Products Division Council. 0.2 This standard was first published in 1973 and is now being revised to align it with IS0 1421-1977 `Fabrics coated with rubber or plasticsDetermination of breaking strength and elongation at break' issued by International Organization for Standardization. 0.3 The strength value determined when a specimen of textile fabric or coated fabric is tested to breaking is not a fixed quantity; it depends on the width and length of the specimen, on its moisture content, temperature and on the speed at which the breaking load is reached. In addition to real changes in specimen strength, errors in observed value can occur through errors of the testing machine and its operation. The testing machine is accurate under static or slow moving conditions, but not so in the case of very rapidly applied load. Failure to ,grip the whole width of specimens leads to partial slip and to less than the fair estimate of strength. At present, therefore, the concept of breaking strength of a coated and treated fabric is an empirical approximation under one-way stretch conditions to the biaxial strength shown by the fabric in actual service. For the sake of general agreement on quality assessment it has become necessary to standardize most of the conditions under which breaking strength of base fabrics should be tested, and as far as possible similar conditions are desirable for coated fabrics. 0.4 For the purpose of deciding whether a particular requirement of this standard is complied with, the final value, observed or calculated, 3 IS : 7016 ( Part II ) - 1981 expressing the result of a test or analysis, shall be rounded off in accordance with IS : 2-1960*. The number of significant places retained in the rounded off value should be the same as that of the specified value in this standard. 1. SCOPE 1.1 This standard breaking strength machines: ( Part II ) covers methods of test for aetermination of and extension at break usipg the following types of a) Constant rate of load, b) Constant rate of traverse, and c) Constant rate of specimen extension. 1.1.1 This method is not suitable for use with products of which base cloth is of mesh construction or with knit fabrics. 2. TERMINOLOGY 2.1 For the purpose of this standard, the definitions given in IS : 2244-1972t shall apply. 3. APPARATUS 3.1 Tensile Testing Machine - All tensile machines shall be provided with means for indicating or preferably for recording both the maximum load applied to the specimen in stretching it to rupture and the corresponding extension of' the specimen. Alternatively any other means to measure extension may be used. Under the conditions of use, the error of the indicated or recorded maximum load at any point in the range in which the machine is used shall not exceed f 1 percent of the load, and the error of the indicated or recorded maximum jaw separation shall not exceed 1 mm. The central points of the two jaws of the machine shall be in &theline of pull, the front edges shall be perpendicular to the line of pull, and their clamping faces shall be in the same plane. The jaws shall be capable of holding the specimen without allowing it to slip, shall be so designed that they do not cut or otherwise weaken the specimen, and shall be wider than the -test specimen. The faces of the jaws should preferably be smooth and flat, but when the specimens cannot be satisfactorily held with flat-faced jaws even with packing, engraved or corrugated jaws may be used. *Rules for rounding off numerical values ( revised ). tGlossary of terms relating to treated fabrics ( firsr rev&n ). 4 IS : 7016 ( Part II ) - 1981 3 mm thick have been found to be suitable NOTE- Pieces of felt approximately for packing. but the choice of type of jaws and packing should be that combination which gives the highest breaking load and does not cause an undtie number of breaks in close proximity to the edges of the jaws. Suitable packing materials for use with either smooth or corrugated jaws include paper, felt, leather, plastics or rubber sheets. 3.1.1 Constant-Rate-@Load Machines - After the first 10 seconds of the test, the average rate of increase of load in any two seconds interval shall not differ by more than 25 percent from the average rate of increase of load over the whole period of the test. The machine shall apply the required load within 60 f 10 seconds. The required load shall be the specified minimum breaking load or, when the minimum breaking load is not specified, the average breaking load as estimated from preliminary experiments. 3.1.2 Constant-Rate-of-Traverse Machines - After the first five seconds of the test, the average rate of traverse of the pulling jaw in any two seconds interval shall not differ by more than 5 percent from the average rate of traverse over the whole period of the test. The rate of traverse of the pulling jaw shall be 100 f 10 mm/min. 3.1.3 Constant-Rate-of-Extension Machines - For machines in which the rate of separation of the clamps is indepen&ent of the extensibility of the material under test, the rate of traverse of the pulling jaw shall be such that rupture is reached in 60 f 10 seconds. 4. TIME LAPSE BETWEEN MANUFACTURE 4.1 For all test purposes AND TESTING the minimum time between manufacture and testing shall be 16 hours, in order to ensure that the material attains dimensional stability due to stress relaxation. 4.2 In order to bind the user and supplier to a stipulated time for carrying out conformity test for supplied material, the following shall apply. 4.2.1 For non product test separate test piece is required for testing. Therefore, the maximum time between the manufacture and testing shall be eight weeks and for evaluation intended to be comparable, the tests as far as possible, should be carried out after the same time interval. 4.2.2 For product test whenever possible the time between manufacture and testing should not exceed six months. In other cases tests shall be made within four months of the date of the receipt of the product by the customer. 5. TEST PIECES 5.1 From the sample, cut test pieces of coated and treated fabric 50 f 0.5 mm wide and of convenient length so as. to permit a free length of IS : 7016 ( Part II ) - 1981 200 mm between the jaws. Five test pieces shall be cut with the length parallel to the warp threads and five test pieces with the length parallel to the weft thread. In case of difficulty, establish the direction of the warp thread by tearing and then cut test pieces parallel to this direction. ' Select test pieces fairly evenly spaced over the full usable length and width of the sample avoiding the selvedge so that no two test pieces contain the same warp threads or weft threads as the case may be. 6. CONDITIONING 6.1 Conditioning - Condition the test pieces at 27 rf 2°C and 65 & 5 percent relative humidity for 48 hours prior to testing. 7. PROCEDURE 7.1 Set the jaws of the testing machine 200 f 1 mm apart. Clamp a test piece centrally in the jaws so that its longitudinal centre line passes through the centre points of the front edges of the grips. Apply the anoropriate pre-tension from the following values: Recommended Pre-tension a) For fabrics up to and including 200 g/ma b) For fabrics over 200 and up to and including 500 g/m* c) For fabrics over 500 g/m2 2N 5N 10 N 7.2 Engage ,any device for reading the breaking load and elongation, put the moving clamp in motion and extend the test piece to the point of rupture under the conditions appropriate for the type of machine being used as specified in 3. Repeat the procedure for each test piece. Nova - If any test piece breaks within 10 mm of line of contact of either of the jaws, record the result; but if-it is found to have broken at a load less than 75 percent of the average of the reinainder of the specimens do not use it in calculating the breaking load. Test another specimen. 8. EXPRESSION OF RESULTS 8.1 Breaking Load - Calculate the mean of the five results for breaking load for each direction and report the values obtained as breaking load in N/50 mm width stating method used. 8.2 Extension at Break - Calculate the mean of the five results in each direction and express this as a percentage of the initial gauge length as follows: Extension at break, percent = Increase in gauge length Original gauge length 6 x, loo ' 4 " IS : 7016 ( Part II) - 1981 ( CQnfinued from page 2 1 Panel for Physical Methods of Test for Treated Fabrics, PCDC 16 : 6 : 1 Convener DR B. R. C. ANAND Representing Plastics and Calicgoozta;micals, Fibres Division. Members Basant Pran Electric Co Pvt Ltd, Calcutta SHRI BASANT KUMAR SHRI J. S. NARULA( Alternate ) Directorate General of Supplies & Disposals, SHR~A. T. BASAK New Delhi SHRI P. K. BASU( Alfernate ) National Organic Chemical Industries Ltd, Bombay SHRI T. S. BIDDA~A DR P. D. TRIWDI ( Alrernute ) Bengal Waterproof Works ( 1940 ) Ltd, Calcutta SHRI B. DLJTM National Test House, Calcutta SHRI A. GHOSH BUREAU OF INDIAN STANDARDS Headquarters: Manak Bhavan, Telephones: 9 Bahadur Shah Zafar Marg, NEW DELHI 110002 11 3239382 Telegrams 323 0131, 323 3375, 323 9402 91 11 3239399,91 Fax : 91 11 3234062, : Manaksanstha to all Offices) Telephone 8-77 00 32 (Common Central Laboratory: Industrial Area, Sahibabad 201010 Plot No. 20/9, Site IV, Sahibabad Regional Central `Eastern Northern Southern T Western Wfices: 32376 17 : Manak Bhavan, 9 Bahadur Shah Zafar Marg, NEW DELHI 110002 : l/14 CIT Scheme VII M, V.I.P. Road, Maniktola, CALCUTTA 700054 : SC0 335-336, Sector 34-A, CHANDIGARH Road, CHENNAI Marol Telephone 160022 600113 Exchange, Andheri (East), 337 86 62 60 38 43 235 23 15 832 92 95 : C.I.T. 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